.btn-xlarge {
    padding: 18px 28px;
    margin-left: 20px;
    font-size: 22px; //change this to your desired size
    line-height: normal;
    -webkit-border-radius: 8px;
       -moz-border-radius: 8px;
            border-radius: 8px;
}

body {
@import url(http://fonts.googleapis.com/css?family=Open+Sans);
  font-family: 'Open Sans';
}
